Which concept describes that a changing magnetic field induces an electric field?

Which concept describes that a changing magnetic field induces an electric field?

• A. Faraday's Law
• B. Gauss's Law
• C. Ampere's Law
• D. Ohm's Law

Answer: (D)

The idea that a changing magnetic field induces an electric field is Faraday's Law of electromagnetic induction. It says that when the magnetic flux through a closed loop changes in time, an electric field is produced around that loop. In mathematical terms, the line integral of the electric field around a closed path equals the negative rate of change of the magnetic flux through the loop. This is why moving magnets or changing magnetic fields generate currents in a coil or transformer—the induced electric field drives the current even without a battery. Gauss's Law relates electric fields to electric charges and the flux through a surface. Ampere's Law relates magnetic fields to electric currents (and, with the full Maxwell formulation, changing electric fields as well). Ohm's Law describes how current, voltage, and resistance relate in conductive materials. None of these capture the specific induction of an electric field by a changing magnetic field in the same direct way as Faraday's Law.

The idea that a changing magnetic field induces an electric field is Faraday's Law of electromagnetic induction. It says that when the magnetic flux through a closed loop changes in time, an electric field is produced around that loop. In mathematical terms, the line integral of the electric field around a closed path equals the negative rate of change of the magnetic flux through the loop. This is why moving magnets or changing magnetic fields generate currents in a coil or transformer—the induced electric field drives the current even without a battery.

Gauss's Law relates electric fields to electric charges and the flux through a surface. Ampere's Law relates magnetic fields to electric currents (and, with the full Maxwell formulation, changing electric fields as well). Ohm's Law describes how current, voltage, and resistance relate in conductive materials. None of these capture the specific induction of an electric field by a changing magnetic field in the same direct way as Faraday's Law.